Polynitrophenols



United States Patent I POLYNITROPHENOLS Carl E. Moore, Chicago, Ill.

No Drawing. Application September 9, 1954,

Serial No. 455,075

7 Claims. (Cl. 23-430) This invention relates to reagents in-theformoftrini trophenols.

The separation or qualitative analysis for barium,

strontium and calcium is particularly difficult, a'ndthe primary objectof the present invention is to enable this;

to be accomplished with relative ease by means of a 3-methyl-S-npropyl-trinitrophenol reagent that will precipitate barium inrelativelylargequantities while having but slight precipitating actionon strontiumand calcium in a mixture containing the three. A furtherobject of the present invention in this connection is to enable analysisto be made for cerium, lanthanum, beryllium, cesium, aluminum, lead,copper, chromium and iron by means of a3-methyl-S-n-propyltrinitrophenol reagent that exhibits contrastingprecipitates for these metals.

A further object of the present invention is:to1 enable lanthanum orlead to be determined in-a mixture containing lanthanum or lead or bothinthepresence of. one or.

more of the following: Nat, Li Cur Ca+t, Mg Ni A1+++ H Z M c cd++ Fe++,Cs+, NH4+ by means. of areagent in the: form of 3-isopropyl-2,4,6-trinitrophenol;

Other andfurther objects of. the present: invention will be apparentfrom the following; descriptionwand claims which, by way ofillustration, show preferredembodiments of the invention and theprinciples thereof and; .what I now consider to bethe best modesinwhiehIhave contemplated applying those principles. Other andfurtherobjects ofthe invention embodying the same or equivalent principles may be usedand changes maybe made as desired by those skilled in the art without.departingfrom the present invention and the purview of the appendedclaims.

I Synthesis of 3-n 1ethyl-5-n-pr0pyltrinitrophenol In each of three 500cc. flasks place 210 cc. (1.6 mole) of ethyl acetoacetate. Chill in anice-salt bath.and,add 0.77 mole butyraldehyde to each flask. Cool-to C.and add, with shaking, to each flask amixturerconsisting of 3: cc.piperidine and .5 cc. ethanol. Maintain eachfiask in an ice-salt bathfor six hours, combinethe contents of the three flasks and refrigeratefor three days while adding an additional mixture of 3 cc. piperidineand5 cc. ethanol each day. After completion of the foregoing, allow thesystem to stand one day at room temperature to obtain the followingester product: t

The yield, a crude bis-ester (viscous oil), is melted on a steam bathand poured into a mixture of 600 cc. acetic acid and 40 cc. concentratedsulfuric acid. To this is added about g. of boiling chips. Reflux forone hour. Pour the mixture (with stirring) into 2 litres of ice-water,establish separate layers by adding ether and decant to obtain theorganic layer. The organic layer thus separated is stirred with 1200 cc.water and neutralized at the same 2,798,793 Patented July 9, 1957 iceonnooon no The aforesaid ether solution is heated gently under reducedpressure until all the ether is evaporated, and to the carbethoxyresidue is added 1020 cc. water, 180 cc. ethanol, and 130 g. NaOH. Theresultant solution is then heated on a steam bath with stirring untilthe ester is dissolved. Reflux for 15 minutes, and then carefullyacidify with a solution of cc. concentrated sulfuric acid in 200 cc.water while cooling the flask with a stream of water; The-acid is addedat a rate compatible with the evoluton of C02. The acidified mixturethus obtained is then refluxed for 15 minutes, cooled to roomtemperature and the layers separated. The crude product thus obtained isdiluted with ether and washed with two 100 cc; portionstof 5%-NaOHsolution followedzby 100cc. of 5% aqueous-acetic. acid. The ethersolution is dried over anhydrous sodium sulfate and distilled underreduced pressure to obtain the following product(3-methyl-5-npropyl-Z-cyclohexene-l-one) having a boiling point of-113C. at9mm.:

5 g. of the 3-methyl-5-n-propyl2-cyclohexene-l-one product is mixed with75 cc. trimethyl benzene (mesitylene-Eastman Kodak crude redistilled)and 1.5 g. of a standard 5% palladium-carbon catalyst. The mixture issubjected to a vigorous reflux at C. for 2 hours and then cooled to 50C. The catalyst, which cannot be reused, is removed by filtration, andwashed with four 5 CCJPOItlOIlS of hot ethyl acetate. The product insolution is subjected to liquid-liquid extraction with. three 40 cc.portions of 10% NaOH solution. The combined extracts are washed with 40cc. pentane, then diluted with 100 cc. water, and 5 cc. of concentratedhydrochloric acid are added thereto. The acidified solution is chilledin an ice bath, further acidified with dilute hydrochloric acid andre-chilled for several hours. The product is removed by etherextraction, and the ether is evaporated under reduced pressure to obtainthe following:

To nitrate the 3-rnethyl-5-n-propyl product, 3 to 4 g. thereof areacidified with 30 cc. of concentrated sulfuric acid, stirred and cooled.30 cc. of concentrated nitric acid are added dropwise while cooling andstirring. The resultant mixture is poured over approximately 50 cc. ofice. When the ice melts, the product in the form of red-black amorphouscrystals is filtered ofl. These are redissolved in 25 cc. of hot ethylalcohol. Then 25 cc. of a 5% NaOH solution are added followed by theaddition of 50 cc. of a saturated KCl water solution. The

A solution of the aforesaid potassium salt.

a following product in the form of bright yellow crystals is cooled andfiltered oif:

N02 NO: 7

CH: CHgOHn-,QH;

V 7 N02 11 Preparation of 3-methyl-5-n-pr0pyltrinitrophenol reagent Addone-half g. of 3-methyl-5-n-propyl-trinitrophenol prepared as above to15-20 cc. water to produce approximately a 3% solution, and add 1 N.NaOH thereto until the pH is adjusted to 6.5. The reagent thus preparedwill produce the following precipitates from an aqueous solution:

Relative Amount of Precipitate Slight.

Minute.

Use of the foreging reagent produces an oil in the presence of thefollowing metals: Be++, Cr++, and Fe+++.

HI Synthesis of 2,4,6 trinitro-S-isopropylphenol I OH: N02

Analysis.-Calci1lated for C9H9N307: C, 39.86; found C, 40.27; H, 3.34;found, C, 3.02; N, 15.5; found, N, 15.2.

IV Preparation 0 2,4,6 trinitr0-3-is0pr0pylphenol reagent For analyticalwork, a sodium salt is prepared of the 2,4,6 trinitro-3-isopropy1phenol.To this end, and aqueous solution of the above identifiedisopropylphenol is first rendered basic by the addition of NaOH, and tothis is added a concentrated water solution of NaCl which precipitatesthe sodium salt of 2,4,6 trinitro-B-isopropylphenol as bright yellowcrystals which may be filtered off. Qualitative tests may be performedby adding a saturated water solution of the sodium salt to diluteaqueous solutions of chlorides or nitrates of the cations being testedwith the following results:

Cation Result Nat. Negative. Li+--. Do. 811: Be. a 0. Mg Do. Ni"- Do.fil tm go. 0. 0 Do. Zn D0. Mn- Do. Or+++ Do. Od .Do. Fe be. 0s Do.

NH4+ Do. La Positive. lb Do.

Ammonia complexes of the following ions give well defined crystallineprecipitates:

I claim:

1. A trinitrophenol derivative selected from the group consisting of3-methyl 5-n-propyltrinitrophenol, 2,4,6- tn'nitro-isopropylphenol andthe sodium salts thereof.

' 2. A reagent for the qualitative separation of barium,- strontium andcalcium consisting of the sodium salt of3-methyl-5-n-propyltrinitrophenol.

3. A reagent for the qualitative separation of lanthanum and leadconsisting of the sodium salt of 2,4,6-trinitroisopropylphenol.

4. 2,4,6-trinitro-isopropylphenol.

5. 3-methyl-5-n-propyltrinitrophenol.

' 6. The method of qualitatively separating barium from barium,strontium and calcium comprising, preparing a reagent in the form of anaqueous solution of the sodium salt of 3-methyl-5-npropyltrinitrophenol,and adding said reagent to a mixture of barium, strontium, and calciumcontained in a solution which contains non-interfering metals toprecipitate only barium in large quantities.

7. The method of performing a qualitative analysis for a metal selectedfrom the group consisting of lanthanum and lead comprising, adding areagent consisting of an aqueous solution of the sodium salt of2,4,6-trinitroisopropylphenol to a solution suspected of containing anion of said metal group, the last-named solution being free ofinterfering material.

References Cited in the file of this patent V .Cousin et al.: Chem.Abstracts, vol. 31 (1937), pg.

7.THE METHOD OF PERFORMING A QUALITATIVE ANALYSIS FOR A METAL SELECTEDFROM THE GROUP CONSISTING OF LANTHANUM AND LEAD COMPRISING, ADDING AREAGENT CONSISTING OF AN AQUEOUS SOLUTION OF THE SODIUM SALT OF2,4,6-TRINITROISOPROPYLPHENOL TO A SOLUTION SUSPECTED OF CONTAINING ANION OF SAID METAL GROUP, THE LAST-NAMED SOLUTION BEING FREE OFINTERFERING MATERIAL.